中文摘要：

目的应用MRI评价鼻咽癌椎前间隙受侵对放、化疗预后的影响。方法回顾分析2005-2007年间经病理证实的初治及无远处转移鼻咽癌患者333例临床资料。所有病例行鼻咽部和颈部MRI扫描并经二维、三维放疗或加化疗。Kaplan—Meier法计算生存率并Logrank法检验，Cox法多因素预后分析。结果随访率95．2％。鼻咽癌椎前间隙受侵139例（41．7％），椎前间隙受侵组较未受侵组T分期、临床分期明显增加（X2=90．41、54．03，P=0．000、0．000）。鼻咽癌椎前间隙受侵组与未侵犯组5年总生存率（OS）、无远处转移生存率（DMFS）及无局部区域复发生存率（LRFS）分别为58．8％与77．5％（x2=11．95，P：0．000），77．8％与85．0％（x2=2．56，P=0．110）及88．3％与91．8％（X2=1．51，P=0．220）。经N分期调整后两组5年0s差异仍有统计学意义（x2=9．93，P=0．002）。多因素分析显示椎前间隙受侵不是影响鼻咽癌OS、DMFS、LRFS的预后因素（x2=0．43、0．08、0．00，P=0．512、0．783、0．971）。结论鼻咽癌椎前间隙受侵发生率较高且比未受侵者的OS低，但椎前间隙受侵不是影响鼻咽癌患者预后的因素。

英文摘要：

Objective To evaluate the prognostic impact of MRI-detected prevertebral space involvement in nasopharyngeal carcinoma （NPC） treated with radiotherapy and chemotherapy. Methods A retrospective analysis was performed on the clinical data of 333 patients who had newly diagnosed biopsy- proven NPC without distant metastasis from 2005 to 2007. All patients underwent MRI scans of the nasopharynx and neck and were treated with two-and three-dimensional radiotherapy without or without chemotherapy. The Kaplan-Meier method was used to calculate overall survival （OS） , distant metastasis-free survival （DMFS）, and locoregional relapse-free survival （LRFS）, and the log-rank test was used for survival difference analysis;the Cox proportional hazards regression analysis was used to assess the prognostic value of prevertebral space involvement. Results The follow-up rate was 95.2%. Prevertebral space involvement was seen in 139 （41.7%） of these patients. The patients with prevertebral space involvement had significantly higher T stage and clinical stage than those without prevertebral space involvement （ X2 = 90. 41, P =0. 000;X2 =54. 03 ,P =0. 000）. The 5-year OS, DMFS, and LRFS for NPC patients with and without prevertebral space involvement were 58. 8% vs. 77.5% （ X2 = 11.95, P = 0. 000） , 77. 8% vs. 85.0%（X2=2.56, P=0.110）, and 88.3% vs. 91.8% （X2=1.51, P=0.220）, respectively. After adjusting for N stage, a significant difference was still seen between the two groups with regard to 5-year OS （ X2 = 9. 93, P =0. 002）. The multivariate analysis showed that prevertebral space involvement was not the independent prognostic factor for OS, DMFS, and LRFS （ X2 = 0. 43, P = 0. 512 ; X2 = 0.08, P = 0. 783 ; X2 = 0. 00, P = 0. 971 ）. Conclusions The frequency of prevertebral space involvement is very high in NPC. The OS for the patients with prevertebral space involvement is significantly lower than those without prevertebral space involvement. But prevertebral space involvement is not the